1. Field of the Invention
The present invention relates generally to service and maintenance solutions for programmable and/or reconfigurable modules, which are included in nodes of a communications network. More particularly the invention relates to a communication module and a method of communicating with such a module.
2. Description of Related Art
The term communication module is here understood to designate arbitrary type of unit, which is adapted to exchange information with at least one other unit over a communications network. The communication module may thus be a line card or an optoelectrical transceiver in a switch or a router as well as a general-purpose computer with networking capabilities.
Data communication equipment such as switches, routers, etc. have until recently had limited maintenance functionality. With today's high capacity networks however, maintenance and reliability are of growing importance. For instance, so-called carrier class services are offered also in data networks. These higher service levels have become cost efficient by use of new technology and methods applied to everything from components to system architecture. An important contribution to the improved reliability and availability comes from surveillance and maintenance functions in combination with modular system architectures that are reconfigurable during operation. There are two main concepts for handling maintenance and control communication between managed parts of the system and the management software. Either the management is accomplished by means of physically separated channels or the management system uses integrated virtual channels, which share the same medium as the payload traffic. The present invention may be used both in networks having physically separated management channels and in networks with integrated virtual channels.
A fair amount of maintenance operations may generally be performed without manual intervention. However, addition, removal and replacement of hardware require manual operations. This is normally also true for software and firmware upgrades. Typically, there is an operator interface towards each node in a communications network. This interface allows an operator to supervise and control various functions in the nodes. The operator interface can be handled via a management computer. Depending on network architecture and the node design (which may have a modular structure), the management computer is either located in a centralized location or connected at one or more suitable points in a distributed system.
Management software often has both fully automatic and various forms of operator assisted operation modes. In its simplest form the management software provides a user-interface for the operator's access to information and control of the system. The earlier generations of management systems for modular systems typically had a majority of their functionality located in a centralized management controller. Any removable modules in a node of a network of this type could hence only perform relatively simple management tasks, such as responding to status requests and actuating simple operating mode commands. Today however, the removable modules are generally equipped with much more management, surveillance and debug functions which may be autonomous to a higher degree. Furthermore, some removable modules may be programmed and configured by loading new software or firmware.
The prior art includes many examples of solutions for remote control of the nodes in a network. For instance, European patent application No. 1 043 868 describes an optoelectronic network interface device, which allows reconfiguration of ports in a local area network (LAN) in response to a control signal from a LAN-administrator, a network control center or being automated via dynamic network reconfiguration software.
European patent application No. 0 917 077 discloses a solution for wireless remote synchronization of data between a personal computer (PC) and a personal digital assistant (PDA). According to the document, data files may be automatically updated through a paging or a cellular digital packet data network, both in the PC and in the PDA.
However, the known distributed management functions for communications networks which include modular nodes may be limited by an insufficient capability of the host system management functionality, which results in that only a subset of the potentially available module functions are, in fact, available on the system level. Limitations of this kind could be due to the fact that the removable modules, although they have a standardized interface and standardized physical dimensions, show considerable differences in management handling properties.
Moreover, there may be limitations with respect to the physical access. For example, a large and physically distributed communications network with centralized management functionality may have modular nodes, which are located in areas where the access to the management system is severely restricted, or perhaps even non-existent. Naturally, this may cause problems when performing debug and repair operations that require operator access to both the management system and the module being diagnosed.